Machine for the manufacture of ribbed piping



Feb. 8, 1938. MORSETH 2,107,831

MACHINE FOR THE MANUFACTURE OF RIBBED PIPING Filed Sept. 15, 1936Patented Feb. 8, 1938 MACHINE FOR THE RIBBED r'mmmic'ruaa or rrrmo LeifMomui, Frydenberg, Ostre Aker, near Oslo, Norway, assignor toAktieselskapet Per Kare,

NorshMotoi- '& Dynamofabrik, Oslo, Norway Application September 15,1936, Serial No. 100,949 In Switzerland September 17, 1935 4Claims.

The present invention relates to a machine for the manufacture of ribbedpiping as for instance described in U. S. Patent No. 1,909,704.

One object of my invention is to provide new and novel means, by meansof which the guiding of the ribbon to the pipe under the manufacture ofthe ribbed piping will take place in a proper ,way. A further object ofmy invention is to construct an arrangement of said guiding means insuch a way that the potential fall in the electric current which is usedfor the purpose of heating the ribbon at a time and before it is woundon to the pipe, shall be as small as possible, due to the by-pass of thecurrent through the said guiding means.

For this purpose, my invention consists in a machine for the manufactureof ribbed piping and comprising-a frame, means for feeding a piperotating about its axis in the axial direction on the said frame andmeans for feeding a metal ribbon to be wound on to the pipesubstantially normal to its axis and electrical means for feeding anelectric current through the said ribbon from a point substantiallyadjacent to thepoint of contact between the ribbon and the pipe to apoint on the ribbon remote from the pipe, guiding means adjacent to thesaid'pipe on both sides of the said ribbon adapted to maintain the saidribbon in proper angular relation to the said pipe, said guiding meanscomprising a plurality of pairs of guiding blocks, mounted on said frameand electrically insulated from each other.

In order that my invention may be readily understood, I shall nowdescribe the same with reference to the drawing which diagrammaticallyillustrates a preferred embodiment of the same.

In the drawing,

Fig. 1 1:99. diagrammatical drawing, showing the complete machine forthe production of ribbed'piping according to my invention.

Fig. 2 illustrates a detail of the machine to a much iarger scale andtaken as a cross section on the line 11-11 of Fig. 1, and

Fig. 3 illustrates also to a much larger scale parts of the machine andthe method of manu facture of the ribbed piping according to my invention.

In the drawing, Fig. 1, l5 denotes the frame of the machine, on which ismounted a driving motor H, for instance of the conventional electrictype, which by gears l8 rotates a gear i9 which extends from'one end tothe other of the frame, and which is journalled in bearings 20 and 2| ateach end of the frame. The pipe I, to be provided with a helically woundmet l r bbon 2 which is supplied from a supply coil of ribbon 22, v isiournalled in a bearing 23 and may'in the free end 24 be held by someholding means, comprising a gear 25 and a shaft 26, iournalled in abearing 21 at the opposite end of the frame I]. An electrical source ofcurrent I supplies electricity to the point 1, preferably where theribbon 3 first contacts with the pipe I, and by means of another contact8 the current is taken out from the ribbon 3 at some distance from thiscontact point 1. By passing a sufficient amount of current through theribbon 3, this will be heated in such a way that it may easily behelically wound around the pipe I, when this is rotated by means of thegear I! and the gear 25. A notch or other means 28 may be arranged toengage with the thread between two windings of the said ribbon 2 andwill tend to move the pipe I in the direction to the right on thedrawing. when the same is rotated, whereby the ribbon 3 will be wound onto the pipe in a helix, as will be understood by anybody skilled in theart.

Close to the point where the ribbon 3 contacts with the pipe I, means l3are provided for guiding the ribbon just before it is bent around thepipe. For the further understanding of the details of this invention,there will now be referred to Figs. 2 and 3.

As above mentioned, Fig. 2 illustrates diagrammatically one part of themachine as above described, looking on it in the direction of the pipeto be manufactured. In this figure, I as be fore denotes the pipe onwhich the ribbon 2 is to be formed in a helix. Electric current is fromthe secondary coil 4 on the transformer, the primary coil 5 of which isfed from some line of electric power, conducted to the point Ipreferably on the inside of the pipe I and is taken out from the ribbon3 by means of an electrode 9 at a suitable distance from the point 1.Due to the passage of this current, the ribbon is heated, and the heatwill of course be highest at the point where the band is wound aroundthe pipe, due to the fact that this part of the band has been under theinfluence of the electric current during the longest period of time. Atthis point where the band is wound around the pipe, rather largestresses will appear. These stresses will tend to bend the band over tothe side in such a way that it will not have the desired angle withreference to the pipe.

According to the invention a number of guiding blocks ll, II, I! andIII, II, I! are arranged at this place, which blocks may be held in aframe II. which although preferably insulated from the frame of themachine I 5, is rigidly mounted on the same.

The guide blocks are of electrically conductive material and, if nomeans were provided to prevent the current from passing from the point Ithrough the guiding block II and the block I3 and further through theguiding block if to the ribbon 3, this passage would constitute a ratherlow resistance shunt over the first partof the ribbon 3, which is to beheated by the of the electric current and consequently the action of thecurrent on this part of the ribbon would be greatly reduced. In order toprevent this, insulating material 161s therefore according to theinvention introduced between the guiding blocks H and i2 and the holdingframe ll. Such insulating material may of course also be arrangedbetween the guiding block Ill and the said frame i3; but this is notreally necessary for the object to be fulfilled. Bythis arrangement oneprevents the great drop of voltage which otherwise would be present, aswill be understood from the following explanation:

Assume that instead of using a plurality of guiding blocks l0, H, I},one uses only one pair of guiding blocks, the total width of the samecorresponding to the sum of widths of the three guiding blocks I 0, H, i2, then the drop of potential over this pair of guiding blocks wouldcorrespond to the potential drop ps, Fig. 3, and the resistance in theguiding block would equal the ohmic resistance of the said guiding blockplus the surface resistance between the guiding block and the ribbon. Bythe division of the guiding blocks into a plurality of pairs of guidingblocks as illustrated in the drawing, the drop of potential over thefirst pair l0, l0 would equal 121, that over the next pair pa, and thatover the last pair pa, and by proper dimensioning of the blocks, theresistance in the current path through one pair of guiding blocks whichis parallel to the current path through the band adjacent to the block,would be large, compared with the resistance in the ribbon, due to thefact that the resistance in the first mentioned by-path to a substantialdegree corresponds to the surface resistance between the band and theguiding block. Therefore, that part of the current which under theconditions according to the invention is not utilized for the heating ofthe band,. will be substantially smaller than that part of the currentwhich would have passed through, if one pair of guiding blocks only hadbeen used, assuming that the said blocks would have had the same totalwidth as the sum of the pairs of guiding blocks used according to thisinvention.

It is, of course, understood that the details of the foregoingdescription with reference to the drawing only must be regarded asexamples, and that a number of guiding blocks to be used must be chosenunder the actual conditions to be met.

I claim:-

.1. In a machine for the manufacture of ribbed piping and comprising aframe, means for feeding a pipe rotating about its axis in the axialdirection and for feeding a metal ribbon, to be wound on to the pipe, tosaid pipe substantially normal to its axis, and electrical means forfeeding an electric current through said ribbon from a pointsubstantially adjacent to the point of contact between the ribbon andthe pipe to a point on the ribbon remote from the pipe, guiding meansadjacent to the said pipe on both sides of the current-carrying sectionof said ribbon to maintain the said ribbon in proper angular relation tothe said pipe, said guiding means comprising a plurality of pairs ofguiding blocks of electrically conductive material mounted on the frameand electrically insulated from each other.

2. In a machine for the manufacture of ribbed piping and comprising aframe, means for feeding a pipe rotating about its axis in the axialdirection and for feeding a metal ribbon, to be wound on to the pipe, tosaid pipe substantially normal to its axis, and electrical means forfeeding an electric current through said ribbon from a pointsubstantially adjacent to the point of contact between the ribbon andthe pipe to a point on the ribbon remote from the pipe, guiding means adjacent to the said pipe on both sides of the current-carrying section ofsaid ribbon to maintain the said ribbon in proper angular relation tothe said pipe; said guiding means comprising a frame, .a number ofguiding blocks of electrically conductive material mounted in saidframe, and electrical insulation between the said blocks.

3. In a machine for the manufacture of ribbed piping and comprising aframe, means for feeding a pipe rotating about its axis in the axialdirection and for feeding a metal ribbon, to be wound on to the pipe, tosaid pipe substantially normal to its axis, and electrical means forfeeding an electric current through said ribbon from a pointsubstantially adjacent to the point of contact between the ribbon andthe pipe to a point-on the ribbon remote from the pipe, guiding meansadjacent to the said pipe on both sides of the currentcarrying sectionof said ribbon to maintain the said ribbon in proper angular relation tothe said pipe; said means comprising a guide supporting frame, guidingblocks of electrically conductive material in the said guide supportingframe and electrical insulation between the said frame and the saidframe of the machine.

4. Apparatus for the production of ribbed piping and of the type inwhich a ribbon is helically coiled upon a pipe and electrically heatedto facilitate the winding of the ribbon upon the pipe, said apparatusincluding guide means adjacent said pipe for constraining said ribbon toa path of travel substantially normal to the axis of said pipe, andmeans for current through the ribbon from its region of contact with thepipe to a point remote therefrom, characterizedby the fact that saidguide means comprises a plurality of pairs of electrically conductiveguide members, and means electrically insulating said guide members fromeach other.

LEI! HORBE'I'H.

